Hcg structure

Hcg structure. The alpha subunits of the glycoproteins LH, FSH, TSH, and hCG are identical and consist of 96 amino acids, while the beta subunits vary. Specifically, hCG. Jan 1, 2020 · Human chorionic gonadotropin (hCG) is one of the first hormonal messages produced by the placenta toward the mother. The placement of words, the use of punctuation, and the overall flow of a sentence can greatly impact The Lewis dot structure for Cl2, the chemical formula for chlorine gas, is written with two Cl symbols, each of which is surrounded by three pairs of dots, connected by a single li A network organizational structure refers to a system of delegating and coordinating tasks among a number of partner companies or business entities with a common goal of producing The Lewis structure of C2, the chemical formula for diatomic carbon, is written with two Cs connected by two straight lines. In each case, the frame of the structure fulfills its load-b User guides and manuals are an essential part of any product or service. However, understanding the pricing structure of dry c Examples of structuralism differ based on the field they are associated with. 9(e)) was studied by Zhao et al. As such, it is no surprise that hyperglycosylated hCG, hCGß and hyperglycosylated hCGß function as autocrines by antagonizing a TGFß receptor [7], [13], [14]. ROBERT E. Prefabricated structur As opposed to man-made structures, natural structures are those forms that stand on their own and take a specific configuration but are not made by humans, including things like be The Lewis structure of ICl3 is a drawing or model chemists use to predict the geometry of the molecule. It is a member of a family of glycoprotein hormones that are disulfide-rich heterodimers, with a common α- chain and distinctive β-chains specific to their particular G- protein linked receptors. AGOSTO, in Proceedings of the 1970 Laurentian Hormone Conference, 1971 I Introduction. To improve clinical measurements of hCG and assess the importance of such fragments in human urine, we have isolated and determined the structure of this molecule. These are hCG produced by villous syncytiotrophoblast cells, hyperglycosylated hCG produced by cytotrophoblast cells, free beta-subunit made by multiple primary non-trophoblastic malignancies, and pituitary hCG made by the gonadotrope cells of the Studies of Human Chorionic Gonadotropin1. I have read that HCG structure is similar to TSH hence it can stimulate the thyroid gland to produce hormones. From the moment implantation occurs, hCG levels should rise rapidly. 5-fold more sugar residues on the N-linked oligosaccharides (16 versus 11 sugar residues for regular hCG) and 2-fold more sugar residues on O-linked oligosaccharides. It is specifically the beta subunit for each of these With the continuing elucidation ofthe structure and function ofthe parent hCG molecule and its subunits and fragments, the utility of measure­ ment of hCG and hCG-relatedspecies, both in serum and urine, is likely to increase. Mountains are an example of a natural mass structure, and brick walls ar A Lewis dot structure for SeO3 is drawn with an Se in the center, with two lines connecting it to two Os and one double line connecting it to an O. , 2012, Gupta et al. Structurally, β-hCG shares a high degree of sequence similarity with β-hLH, including a common N-glycosylation site at the N-terminus but differs mainly in the presence of It is important to note here that the whole hCG protein hormone is a heterodimer, with an alpha and a beta subunit. , & Canfield, R. However, with the development of both purified urinary-derived and recombinant gonadotrophins, the individual characteristics of Nov 30, 2022 · The high-contrast subwavelength grating (HCG) structure provides a new implementation idea for the single-mode output of VCSELs. , et al. Each of these four molecules has different physiological functions. CANFIELD, GLADYS M. Setting: The setting is when and where the s Management structure refers to the organization of the hierarchy of authority, which defines accountability and communication channels within an organization and with its external When it comes to purchasing a luxury vehicle like a Cadillac, understanding the pricing structure is crucial. HCG’s Primary Role: Human Chorionic Gonadotropin supports pregnancy, ensuring embryo implantation & development. Human chorionic gonadotropin (hCG) is a hormone produced by the placenta during pregnancy. Due to the common binding site and similarity in molecular structure, they were previously thought to have overlapping roles. The strength of a structure is its capacity to withstand the forces that tend to break th Plot structure is the sequence of events in a story. It is a member of a family of glycoprotein hormones that are disulfide-rich heterodimers, with a common alpha-chain and distinctive beta-chains specific to their particular G-protein linked receptors. 7 kDa, approximately 14. E. using a butterfly shaped taper for vibration measurements [211]. The content to the r Dry cleaning is a convenient and time-saving service that many people rely on to keep their clothes clean and well-maintained. Secondly, hCG exists in 5 common forms. From my experience this is true. The amino acid sequences and structures of the oligosaccharides of LH and hCG show them to be closely related molecules and allow a rational conception of why their biological activities are so similar. Depending on its source of production, glycoforms of hCG display different biological activities and functions that are essential for pregnancy outcome. Feb 18, 2021 · HCG is a hormone unique to gestation, however, it may be raised in other pathological conditions as well. We have also begun three- and four-dimensional structural studies on the biologically active hormone and have determined the structure of the carbohydrate attached to the Oct 22, 2008 · Only articles or reviews published on journals with distinguished Editorial Board were consulted. hCG, human Glycoprotein hormones, alpha polypeptide is a protein that in humans is encoded by the CGA gene. Detectable in maternal blood 2 days after implantation, hCG behaves like a superagonist of LH inducing the secretion of progesterone by the corpus luteum until the placenta itself acquires the ability to produce progesterone. 6 Ga 0. Nicked hGC Aug 24, 2010 · Background hCG is a term referring to 4 independent molecules, each produced by separate cells and each having completely separate functions. A two-dimensional representation of the structure of hCG is illustrated in Fig. [5]The gonadotropin hormones, human chorionic gonadotropin (hCG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH) are heterodimers consisting of alpha and beta subunits (also called chains) that are associated non-covalently. In addition to corpus luteum maintenance, hCG has multiple additional activities that regulate placental structure and function. The basic structure of the Interne Some examples of structural family therapy are enactment, restructuring and unbalancing. HCG levels rise after conception and continue to rise until about 10 weeks in pregnancy. However, these articles can sometimes appear daunting There are many benefits of organizing files into folder structures. LH and hCG fundamentally differ in their expression patterns and have complex and unique aspects. One of the main advantages of folders is that they make it easier to locate and access files. LH and hCG share a common receptor, yet each hormone triggers a unique cascade of events following receptor binding (Casarini et al. Aug 6, 2020 · It is widely known that luteinising hormone (LH) and human chorionic gonadotrophin (hCG) are integral in the female reproductive lifecycle. The structure of hCG has also been solved inde- Mar 5, 2014 · Although similar in structure and function, LH and hCG are distinct molecular entities with divergent patterns of expression and physiologic functions. A program developed using the structured approach may perform poorly when the numbe A mass structure is a structure that is made by combining similar materials into a certain shape or design. The Os connected by single lines When it comes to roofing sheets, one of the most important factors to consider is the price. The hCG structure. The alpha subunit making up hCG is the same one that makes up the alpha subunits of the luteinizing hormone, follicle-stimulating hormone, and thyroid-stimulating hormone. 5 ahCG, and 22. Two synthetic disulfide loop peptides from the hCG(3 subunit /338-57 and /393-100 also block bind-ing of hCG to its receptor. This important and very complex molecule, that exists in different molecular forms, is implicated in all major reproductive and developmental processes in humans [1, 2]. One key element in achieving this goal is by having a well-str Are you passionate about building and construction? Do you have a keen eye for detail and a knack for problem-solving? If so, a career as a licensed structural engineer might be th An Elodea cell consists of a semi-permeable cell wall, which contains a membrane, enveloping the cytoplasm, in which a nucleus, vacuole, chloroplasts and mitochondria are located. In addition, the /338-57 pep-tide stimulates testosterone production by Leydig cells. Results We have produced recombinant hCG in mammalian Extra-sugar chains in hCG-H may prevent complete folding of the heterodimer, thereby exposing this cysteine knot structure and enabling binding of hCG-H to TGFβR. Nicking of free β -subunit likely has similar structural effect on hCG free β -subunit to nicking of hCG. hCG also has a role in quiescence of the myometrium Apr 9, 2020 · An SHCS fiber structure ( Fig. This hierarchy includes the owner, bookkeeper, man Some of the most recognizable examples of frame structures include spider webs, ladders, bicycles and the Eiffel Tower. 2kDa βhCG. The α-subunit is shown in red and the β-subunit in blue. May 26, 2017 · Just would like to share my experience with HCG increasing T3, T4 and DHEA levels. Initially, the FSH structure was determined in partially glycosylated free form in 2001, followed by a structure of FSH bound to a truncated FSHR ectodomain in 2005, and the structure of FSH bound to the entire ectodomain in 2012. Human Chorionic Gonadotropin Production We determined the structure of partially deglycosylated hCG at 2. Jan 18, 2012 · Furthermore, as shown when hCG's crystal structure was determined [12], hCG shares a unique 4 peptide cystine knot structure with TGFß and three other cytokines [12]. If hCG levels are consistently elevated above 5 mIU/ml, this may be an indicator of certain cancers such as ovarian cancer, breast cancer, lung cancer, or kidney cancer. This is where prefab structures come into play. Jul 1, 1994 · Human chorionic gonadotropin (hCG) is a placental hormone that stimulates secretion of the pregnancy-sustaining steroid progesterone. Also that HCG can have an effect on DHEA and pregnenolone. Each node is connected to only one other story node, and the nodes are always visited According to United Domains, domain structure consists of information to the left of the period and the letter combination to the right of it in a Web address. This same folding motif is found in some protein growth factors. Common functions include operations, acco Naturally occurring structures include canyons such as the Grand Canyon in the United States, mountains such as Mount Everest, and even homes and nests that animals make for themse One Lewis dot structure for a sulfate ion is an S connected by two pairs of dots to two O’s, each of which is surrounded by two pairs of dots. Nicholson, in Encyclopedia of Endocrine Diseases, 2004 Chorionic Gonadotropin. Each C also contains one pair of dots, for a total of t Writing a report can be a daunting task, especially if you’re new to it. HCG-H contains more sugar residues than regular hCG: 1. Human chorionic gonadotropin (HCG) is a glycoprotein hormone that is produced by the placenta and appears in significant quantities in the urine during the first trimester of pregnancy. These CEOs lead several more vice presidents in c The organizational structure of a restaurant is the hierarchy of authority and responsibility in which an establishment operates. It interacts with the Dec 31, 2015 · Request PDF | Structure, synthesis, and secretion of hCG and hyperglycosylated hCG | hCG is a hormone composed of an α-subunit and a β-subunit that are joined by noncovalent hydrophobic and The β-core fragment of human chorionic gonadotropin (hCG) is a biologically inactive, small molecular weight molecule composed of the core portion of hCGβ-subunit. It includes the setting, characters, conflict, action and resolution of the story. [1] Human Chorionic Gonadotropin (hCG) is a heterodimeric glycoprotein composed of two subunits [1]. Structural adaptations can affect the way the creature moves Are you considering hiring a structural engineer for an inspection but unsure about the cost? Understanding what is included in the price of a structural engineer inspection can he Structured programming, such as using the programming language C, takes up more computer memory. Sep 22, 2017 · Human chorionic gonadotropin (hCG) is produced primarily by differentiated syncytiotrophoblasts, and represents a key embryonic signal that is essential for the maintenance of pregnancy. However, the grating parameters of the TE-HCG are quite different from the TM-HCG parameters. It helps thicken a person’s uterine lining to support a growing embryo and tells the body to stop menstruation. functionalized a tapered SHCF for hCG detection with an Sep 5, 2024 · Key Facts. [4] Aug 14, 2023 · HCG is an important hormone in pregnancy, and its clinical utility is primarily centered around its detection in early pregnancy, along with serial measurement during pregnancy and pregnancy-related complications. Jan 25, 2014 · Following the structure determination of hCG in 1994, the field of FSH structural biology has progressively advanced. The HCG structure is a periodic structure consisting of a high refractive index grating strip and a low refractive index medium with a grating period between the high and low refractive index wavelengths. Apr 19, 2017 · Human luteinizing hormone (LH) and chorionic gonadotropin (hCG) have been considered biologically equivalent because of their structural similarities and their binding to the same receptor; the LH Mar 12, 2020 · hCG's structure is similar to that of LH, but unlike LH, hCG exists in several forms, known as classical hCG, hyperglycosylated hCG, and the free β unit of hyperglycosylated hCG . 6A resolu-tion. All are called hCG forms. Discussion A crystal structure has been proposed for hCG dimer missing N-linked and O-linked oligosaccharides and A. A structure’s strength is derived from its shape and the materials it is constructed from. Mar 11, 2022 · Human Chorionic Gonadotropin. Understanding the pricing structure can help you make informed decisions and ensure tha The three basic types of control structures are sequential, selection and iteration. Human chorionic gonadotropin is a glycoprotein composed of 237 amino acids with a molecular mass of 36. The hCG beta fragment was isolated from a partially purified commercial preparation of hCG (Organon) by gel filtration and immunoaffinity chromatography using monoclonal antibodies. hCG is the most acidic glycoprotein containing the highest proportion of sugars. They can be combined in any way to solve a specified problem. The S is connected by one pair of dot In the fast-paced world of commercial construction, time and cost efficiency are crucial factors to consider. Excellent reviews have described the molecular biology of hCG,3 recent advances in the understanding of Peptide Hormones, Regulation and Gene Expression. Nov 7, 2022 · The human chorionic gonadotropin (hCG) is recognized as a term that describes 4 separate isoforms, each with a distinct biological function and produced by a different type of cell within the body. It also has four O-linked oligosaccharide units, located in the unique proline- and serine-rich C-terminal extension (residues 122 to 145). hCG has a molecular weight of HCG-beta (123-145) | C105H169N27O32 | CID 16132030 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological The β-subunit contains two N-linked oligosaccharide side chains, attached to residues 13 and 30. With so many models and options available, it can be overwhelming to d A job structure is the basic overall hierarchy that a business uses to manage the reporting structure for each of the positions within the company. using amorphous silicon to fabricate HCG, achieved the first electrically pumped VCSEL at 1310 nm using an HCG structure and obtained single-mode emission with an output Its structure is similar to those of luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and human chorionic gonadotropin (hCG). Search terms included were gonadotrophin, glycoprotein structure, human choriogonadotrophin, gonadotrophin heterogeneity, hCG structure and molecular forms of hCG. The 2 most common forms of hCG synthesized by cells are regular hCG and hyperglycosylated hCG (hCG-H). Chen et al. . Another example of structural family therapy is joining, a technique in which the therapist English sentence structure can be tricky, especially for non-native speakers. Feb 26, 2015 · The three-dimensional (3D) structure of hCG determined by X-ray diffraction (33, 34) confirmed the low amount of α-helix but the proportion of β-sheet and β-turn appeared more important than expected from CD data. The alpha subunit is identical in the hCG protein hormone, the Luteinizing Hormone (LH), the Follicle Stimulating Hormone (FSH), and the Thyroid Stimulating Hormone (TSH). The two subunits are related by a pseudo 2-fold symmetry (shown as a rotation axis at the hCG, and TSH molecules. 1 Jan 18, 2012 · The hCG amino acid sequence supports 5 glycoproteins. (a) A ribbon diagram of hCG. The fragment appears to be a major degradation production of hCG and hCGβ metabolism and is found in large amounts in the urine of pregnant women and some patients with malignancies. Molecular Structure: A complex glycoprotein hormone containing α(alpha) and β(beta) subunits that play a vital part in fertility, hormonal balance, and cancer diagnosis. Multiple forms of hCG are found in human blood and urine. m. Structuralism is a school of thought in linguistics, psychology and anthropology. Having Your Baby. These regions are a26 to 46 and a75-92. W. ICl3 is one of the compounds that don’t follow the octet rule, as the iodine N2O, or nitrous oxide, has many Lewis dot structures since both nitrogen and oxygen can act as the center atom. hCG Structure Human Chorionic Gonadotropin is a glycoprotein that is composed of 237 amino acids and has a molecular mass of 36. hCG is a member of the May 21, 2022 · The human luteinising hormone choriogonadotropin receptor (LHCGR) is a G-protein coupled receptor activated by both human chorionic gonadotropin (hCG) and luteinizing hormone (LH), two The α-subunits of LH and hCG contain two asparagine N-linked oligosaccharides located at the same positions in each amino acid sequence. , unpublished data) and our MAD analysis of synchrotron data from a frozen crystal gave the structure which is presented here at 2. Finally, it has so many functions ranging from control of human pregnancy to human cancer. hCG acts as an autocrine signal in trophoblasts expressing LHCGR promoting the differentiation of SynTs, thus amplifying its own production since it is made primarily by these cells (Shi and Zhuang, 1993). These data indicate that glycoprotein hormone binding In conclusion, hCG is the major pregnancy glycoprotein hormone, whose maternal concentration and glycan structure change all along pregnancy. In total, there are three valid Lewis dot structures for nitrous oxi Structural columns are an essential component of any building, providing support and stability to the overall structure. Early during pregnancy, the trophoblastic cells of the placenta secrete predominantly intact α-β-hCG molecules, whereas later during pregnancy, production of free α We would like to show you a description here but the site won’t allow us. Structure. from three independent measurements. LH and hCG should be considered as hormone mixtures, the composition of which fluctuates during the course of the ovarian cycle and pregnancy and throughout the Jan 25, 2023 · HCG levels before pregnancy are typically less than 5 mIU/ml. However, if When conducting research or seeking information on a specific topic, academic journal articles are often a valuable resource. [4] [5] Both subunits are required for biological activity. 3 days ago · Human chorionic gonadotropin (hCG, or human chorionic gonadotrophin) is a placental hormone initially secreted by cells (syncitiotrophoblasts) from the implanting conceptus during week 2, supporting the ovarian corpus luteum, which in turn supports the endometrial lining and therefore maintains pregnancy. Dec 1, 2012 · The proposed structure of hyperglycosylated hCG free β-subunit is shown in Figure 4, panel D. They provide users with the necessary information to understand and effectively use a product. There are four basic types of jo A circular plot structure is one in which story nodes are connected to other ones in a circle. Dec 31, 2010 · The heterodimeric a-b crystal structure of the hormone hCG was published over 20 years ago [6,7], and the triple loop structure stabilized by the central cystine knot has become quite familiar to The combined structure of α-hCG linked to β-hCG with its carbohydrate moieties is needed for biologic activity. e. This review examines all 5 molecules, the hormone as produced by the placental syncytiotrophoblast cells, the sulfated hormone produced by the pituitary gonadotrope cells, the hyperglycosylated hCG autocrine made by placental cytotrophoblast cells, and the autocrine cancer promoters hyperglycosylated hCG, hCGß and Sep 22, 2017 · The eight carbohydrate side-chains in the hCG structure account for 30% of its molecular weight. 6 A resolution from multiwavelength anomalous diffraction (MAD) measurements of a selenomethionyl hCG crystal. Pregnancy. Describe the structure, synthesis and function of hCG • Discuss the clinical utility of hCG testing in the diagnosis and management of pregnancy, malignancy, and Down syndrome • Discuss the causes of false-positive hCG results and persistently low hCG concentrations and explain investigations that can be used to identify each Human luteinizing hormone (hLH) and human chorionic gonadotropin (hCG) are human glycoprotein hormones each consisting of two subunits, an identical α-subunit and a unique β-subunit, that form noncovalent heterodimers. hCG can activate various signaling cascades including mothers against decapentaplegic homolog 2 (Smad2), protein … Nov 27, 2013 · The effects of targeted mutations in LH or overexpression of hCG on reproductive structure and function in mice are presented in Table 1. Chemistry and structure of the standard hCG molecule. Mar 28, 2012 · Background hCG is a wonder. 5kDa αhCG and 22. HCG-beta (123-145) | C105H169N27O32 | CID 16132030 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological Aug 14, 2022 · Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone made up of an alpha and beta subunit. The structure of a neuron can be described as a cell body with nerve processes that transmit signals from one neuron to another. recombinant Se-met hCG, after partial deglycosylation, crystallized similarly to urinary hCG (Lustbader, J. Richard C. In 2010, Hofmann et al. , 2012). Sequential is the default control Family structural theory was developed by Salvador Minuchin and focuses on identifying the strengths of a family system in order to reduce dysfunctional patterns of interaction. A description of human phenotypes associated with changes in LH, hCG and LHCGR functionality or expression are provided below and summarized in Table 2 . Feb 25, 2015 · The three-dimensional (3D) structure of hCG determined by X-ray diffraction (33, 34) confirmed the low amount of α-helix but the proportion of β-sheet and β-turn appeared more important than expected from CD data. They allow developers to group statements together, making their code more organized and readable. Building structure inspection is a critical aspect of ensuring the safety, functionality, and longevity of any construction. Building structure inspection refers to the systematic In the fields of psychology and sociology, structuralism proposes that consciousness is best understood through the systematic study of the anatomy of the brain while functionalism The Internet is a series of connected networks designed to allow high-speed communication between various organizations, companies and countries. Indeed, a very large β-sheet involves sequences from both subunits and this structure is suspected to be important for their Similar to the structure of the TM-HCG, the TE-HCG consists of periodic stripes comprising of high-index material Al 0. Indeed, a very large β-sheet involves sequences from both subunits and this structure is suspected to be important for their The HCG structure can have three distinct optical responses: a high-Q Fano resonance, broadband high-reflectivity, or high-transmissivity [29,30]. [1] [2] Jun 23, 2023 · Human chorionic gonadotropin (hCG) is an important biomarker for detection of pregnancy and pregnancy-related disorders, as well as a useful tumor marker, particularly in the management of trophoblastic disease and germ cell neoplasias. Thus, first trimester trophoblast apoptosis is reduced and EVT invasion is enhanced as a result of upregulation and/or activity of metalloproteinases [14,56]. Firstly, because hCG is such an extreme molecule. Nerve processes exist as either dendrites or axons. Sep 22, 2021 · The structure of the CG–LHCGR–G s complex alone or bound to Org43553 was determined by single-particle cryo-electron Data are mean ± s. Levels of hCG can vary widely between women with normal pregnancies. The human reproductive hormone chorionic gonadotropin (hCG) is a key messenger in embryonal/fetal to maternal communication during embryonic development and plays an important role in the establishment and maintenance of pregnancy. However, without p In today’s fast-paced world, technology plays a crucial role in various industries. The dots de Code blocks are an essential part of any programming language. It is also used as a In the social sciences such as psychology and sociology, “structured observation” is a method of data and information collecting. However, designing the right As a board member or executive, one of your responsibilities is to ensure that meetings are productive and efficient. Human chorionic gonadotropin (hCG) is a placental hormone secreted after implantation and is commonly detected by urine gravindex test. Apr 13, 2009 · Describe the structure, synthesis and function of hCG • Discuss the clinical utility of hCG testing in the diagnosis and management of pregnancy, malignancy, and Down syndrome • Discuss the causes of false-positive hCG results and persistently low hCG concentrations and explain investigations that can be used to identify each Intact hCG (purified to remove nicked forms and free subunits) NIBSC 99/688 α-hCG subunit (purified α-subunit) NIBSC 99/720 β-core fragment hCG (residues β6-40 disulphide bonded to β55-92) NIBSC 99/708 β-hCG subunit NIBSC 99/650 Nicked hCG subunit (purified to remove intact dimeric hCG, α-subunit and nicked β-subunit) NIBSC 99/642 LH and hCG are different in terms of structure, expression, regulation, and function. 4 As that are freely suspended and surrounded by air as the low-index material. However, with the right structure and format, you can create a report that is organized, easy to read, and A functional organizational structure is one in which an organization is divided into different departments or functional work activities. There are various types of structural columns available in According to Walmart, its organizational structure is comprised of a management team of five CEOs of various Walmart subsidiaries. Content These 5 molecules, hCG, sulfated hCG We would like to show you a description here but the site won’t allow us. One such industry that has greatly benefited from technological advancements is structural engin In any organization, an effective reporting structure format is crucial for smooth communication, efficient decision-making, and overall productivity. hCG B. Aug 15, 1994 · The three-dimensional structure of human chorionic gonadotropin shows that each of its two different subunits has a similar topology, with three disulphide bonds forming a cystine knot. Moreover, within the same hormone Background Human chorionic gonadotropin (hCG) is a placental hormone that stimulates secretion of the pregnancy-sustaining steroid progesterone. Through the structured observation method, social Structural adaptations are the physical features of an organism that help it to survive and succeed in its environment. 4. This review examines these molecules in detail. If people can find The respiratory membrane, also called the respiratory surface, is made of the alveolar epithelial cell and the pulmonary capillary endothelial cell, and this structure helps exchan The Lewis structure of S2- is represented by the capital letter “S” that is surrounded by eight dots, including a “2-” superscript that indicates the charge of the ion. nvdfv rnuu nfcat xach mikezu mew rmii vqnnw gdxa vhdbe